Botulinum Toxin Injections for Children With Excessive Drooling

Abstract

The objective of this study was to evaluate the feasibility of ultrasonography-guided injections of botulinum toxin A into the parotid glands of children with severe drooling (sialorrhea). Excessive drooling is common in children with chronic neurologic disorders. Preliminary observations in adults suggest that injections of botulinum toxin A into the parotid glands can decrease drooling, but the optimal dose, sites of injection, and concomitant use of imaging during injections and its use for children have not been established. Ultrasonography was used to guide the injection of botulinum toxin (10-25 IU) into both parotid glands of nine children with excessive drooling. Subjective and objective measures of the severity of drooling were collected before and after botulinum toxin A injections. A booster injection was provided if the initial response was inadequate. Injections were well tolerated, and no adverse reactions were observed. Ultrasonography revealed that the parotid gland showed a variable depth, extent, and vascularization. Eight of nine patients needed a booster injection after 1 month. Objective measures of drooling severity were improved in seven of nine patients. However, subjective improvement was reported in only three of nine patients, and this improvement was functionally significant in only one patient. Although intraparotid injection of botulinum toxin A is safe and causes a reduction in saliva production in children, the doses used in this study did not result in functionally significant improvement. Higher doses of botulinum toxin A in the parotid glands or concomitant injections into the submandibular glands can increase the efficacy of these injections. Variability in size, depth, and vascular supply of the parotid gland suggests the importance of ultrasonography guidance for optimizing injections. These results underscore the need for further studies to establish the efficacy of this treatment in children.